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go/test/escape_unsafe.go
Matthew Dempsky 556b3f5bdf test: add regress tests for unsafe.Pointer rules
Updates #23109.

Change-Id: I55f7860c868acc948a6397ab6a9295e177724a56
Reviewed-on: https://go-review.googlesource.com/c/go/+/170450
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-03 16:03:55 +00:00

70 lines
2.2 KiB
Go

// errorcheck -0 -m -l
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Test escape analysis for unsafe.Pointer rules.
package escape
import (
"reflect"
"unsafe"
)
// (1) Conversion of a *T1 to Pointer to *T2.
func convert(p *float64) *uint64 { // ERROR "leaking param: p to result ~r1 level=0$"
return (*uint64)(unsafe.Pointer(p))
}
// (3) Conversion of a Pointer to a uintptr and back, with arithmetic.
func arithAdd() unsafe.Pointer {
var x [2]byte // ERROR "moved to heap: x"
return unsafe.Pointer(uintptr(unsafe.Pointer(&x[0])) + 1)
}
func arithSub() unsafe.Pointer {
var x [2]byte // ERROR "moved to heap: x"
return unsafe.Pointer(uintptr(unsafe.Pointer(&x[1])) - 1)
}
func arithMask() unsafe.Pointer {
var x [2]byte // ERROR "moved to heap: x"
return unsafe.Pointer(uintptr(unsafe.Pointer(&x[1])) &^ 1)
}
// (5) Conversion of the result of reflect.Value.Pointer or
// reflect.Value.UnsafeAddr from uintptr to Pointer.
// BAD: should be "leaking param: p to result ~r1 level=0$"
func valuePointer(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
return unsafe.Pointer(reflect.ValueOf(p).Pointer()) // ERROR "p escapes to heap"
}
// BAD: should be "leaking param: p to result ~r1 level=0$"
func valueUnsafeAddr(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
return unsafe.Pointer(reflect.ValueOf(p).Elem().UnsafeAddr()) // ERROR "p escapes to heap"
}
// (6) Conversion of a reflect.SliceHeader or reflect.StringHeader
// Data field to or from Pointer.
func fromSliceData(s []int) unsafe.Pointer { // ERROR "leaking param: s to result ~r1 level=0$"
return unsafe.Pointer((*reflect.SliceHeader)(unsafe.Pointer(&s)).Data)
}
func fromStringData(s string) unsafe.Pointer { // ERROR "leaking param: s to result ~r1 level=0$"
return unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&s)).Data)
}
func toSliceData(s *[]int, p unsafe.Pointer) { // ERROR "s does not escape" "leaking param: p$"
(*reflect.SliceHeader)(unsafe.Pointer(s)).Data = uintptr(p)
}
func toStringData(s *string, p unsafe.Pointer) { // ERROR "s does not escape" "leaking param: p$"
(*reflect.SliceHeader)(unsafe.Pointer(s)).Data = uintptr(p)
}